Wednesday, November 3, 2010

Lots Going On

I'm back after a month hiatus or so. Figures I'd get too busy to blog right as so many juicy "write about me" sort of things happen. To be honest, I hope you've wondered what my take is. Not that I'm some security guru, or the man in the know, but because it means you are interested in this stuff and realize I am too, wanting to hear more about what I am seeing from the trenches.

Either way, here is my take on the last month, plus a peek at what is coming down the pike/pipe.

ASP.NET Oracle Thingy

So this was a biggie for .NET developers, ASP.NET developers in particular. As you likely know by now, it had nothing to do with Oracle Corporation or any of their technology. I won't explain what it was, since others have done better than I ever could. The vulnerability hit the internet blog posts mid-September and a fix was in place soon after. Microsoft ranked it as a big deal, though my first glance at it was no big deal. I still think they made it a bigger deal than it needed to be, but honestly it was refreshing to see such movement and activity on it. So why didn't I think it was a big deal? It was something that would take some time to exploit. Sure, the payloads of web.config files and all that would be worth it, but it takes quite a bit of exploit attempts to get the thing to work.

Now, to play the other side of things, which I enjoy doing as well, I REALLY hope you have applied the patch Microsoft gave you for your servers! My lack of whizbang about the issue doesn't mean I find it something to ignore. In fact in this case it is the opposite. The noise and commotion over this vulnerability makes hackers go "ooooh, pretty lights..." and head TOWARDS the issue. If they weren't trying it before, they sure are now. I have no formal study-borne proof of my assertion, but I know human nature. Didn't it cross your mind just a little as to whether YOU could execute it? I did mine. I thought it would be cool to write a routine that ran through some stuff and tried it over and over, even if only on my localhost. The truly bad guys/gals are too. And for some reason this exploit seems accessible to novices...it isn't all complicated I guess.

Anyway, PATCH YOUR SERVERS if you haven't already.

Lots Of Us In The News

Ok. So not me and likely not you. But we have to understand that though it was "them", "thems is us". How close are you or me from being a negative headline? In the last month news broke about healthcare data compromised, bank accounts broken into, Twitter hacked using onMouseOver javascript to send you to your favorite porn site faster, Twitter had a password-stealing phishing scam hit many people including CNN anchor Rick Sanchez (though it was a rather amusing hack), Facebook had at least one notable issue, and the SCADA attack showed us how subtle, intense and intelligent pockets of the hacker community are. The SCADA one in particular causes me anxiety. Facebook, Twitter, etc...close your holes already and adjust with the zillions of people who are on your systems. Not that these were avoidable in every case, but keep being diligent on closing holes. If you are popular then you are a huge target.

The SCADA one, however is different. Getting people to download a piece of software silently by just visiting a website, having your machine attack a single system in a concentrated effort, knocking that system down and still not being sure who attacked it...that to me is scary. Now, granted, where did it all start? Getting people to download software. They can either be silly enough to just surf to random sites where the software sits, or it is a good site that they go to that is silly enough to not close its holes. Again, Cross-Site Scripting and SQL Injection can really put the hurt on and allow lots of other attacks get the foothold they need to go forward.

Looking Forward

I don't like to look too far forward in this field. It is a lot harder to predict than general technology or programming. But this is so clear and getting clearer every day. What is happening is that hackers are looking more at the application layer and developers are lagging more than ever. As we educate the good guys, we point out our flaws to the bad guys. And frankly, they have more to gain in attacking than we do in defending. Defense costs money and if you do it right you have nothing to show for it. "Hey boss! I need a raise! Nothing has hit us for a year!" Uh, yeah. Unfortunately, if nothing has hit you, it could be you are really good at defending or that hackers just haven't given you the time of day yet.
I am predicting a higher use of CSRF and that is coming to pass. I am also predicting that we are just seeing the tip of the iceberg on successful, intelligent attacks. SCADA, though somewhat complicated and highly organized, wasn't all that difficult. We still have the easy holes to plug. Once we plug those, and I don't know that we ever will completely, they will be a few steps ahead of us, ready and waiting with more complex attacks. I'm a glass half full guy, really I am, but the state of software security has me wondering WHEN not IF a large full-scale attack will wipe out the internet for an extended period. The bad guys are already taking our money from our accounts, stealing data from our companies, attacking our systems and they already are doing it rather silently. They are growing in understanding and savvy. We aren't. We aren't. We aren't.
Our bosses still expect us to make our sites 100% secure (impossible), and they are not training the rank and file developer on security. "You are the security folks. I count on YOU." But we can't follow every developer and do code reviews...it isn't feasible. We are still building crappy software and sites full of holes. And if you aren't even sure what the holes are in your code, shame on you but you aren't alone. Let me know if I can help. I am willing to educate you, point you to awesome training materials and sites, look at your code, build something for you. It really is time to get off the sidelines.

Saturday, September 18, 2010

CSRF On The Rise

If you have heard any of my talks in 2010 you know how scary CSRF (Cross-Site Request Forgery) is and how I think it will be taking off and going from #5 in the OWASP Top 10 to #3 (hard to top SQL Injection and XSS at #1 and #2). It hasn't gotten a lot of press, and there hasn't been a ton of action on that front by the bad guys...yet.

But this week an article in DarkReading about CSRF came out that shows it is starting to increase. My comment at the bottom of the article should sound familiar to those of you watching this blog (I think there are 4 or 5 of you out there, right? ) -- the press and the noise is still about patching and server-side, network-facing solutions. They are band-aids and stitches fixing holes that will continue and continue until developers learn to code more securely.

"Blah blah blah" some of you may be saying. "Same old same old. Show us something more, Greg." Well, if you thought that, or said it out loud, I have to ask "Are you actively coding against SQL Injection and Cross-site Scripting?" If you are, and my spiel sounds old, then it is time to move on away from here. And CONGRATULATIONS, Grasshopper! You have become a better developer and that is a success for us both in my book!

For the rest of you, please dig in. Read my previous posts and go to sites like OWASP and ha.ckers.org and see how to code against SQL Injection and Cross-site scripting. These two things alone will help us all.

So what about CSRF? What can I do about it? The short answer is that the hole is plugged at the destination of the attack, and that is by validating all actionable requests thoroughly. Huh? I will do more posts about CSRF, what it is, how it works, but in general it is that you have to make sure requests come from someone you know already, that has logged in and has a specific signature or footprint so you know every request that comes from that person. Analogy time -- if someone came to your door, 6 ft and blonde, and hands you their username and password, then you can generate a ticket and session for them. If someone 5' and brunette comes to the door with the first person's ticket, is it the first person? Obviously not, but our web servers only look at the ticket! If you have the ticket you MUST be the right person. Ouch! This is what makes CSRF work, executing an action on someone else's behalf. So the solution is to look for the 6ft blonde on each request using that ticket. For you .NET folks that solution is via the ViewStateUserKey. ViewStateUserKey can be set to the session id of the current user and that will be enough to show the server it really is the right person. The hacker won't have viewstate in a link, and if they try to create a whole form to do the work it won't have the current session in it. Ahhh...much better! (Side note about it not being perfect found in this article.)

So now maybe I will have to harp on proper CSRF coding as well as SQLi and XSS...

Wednesday, August 25, 2010

Great Training

I just took this course, in order to prepare for the GSSP-.NET certification and they've updated it to be language agnostic and cover what is really necessary and important for web developers to know. It focuses on the OWASP Top 10 you hear me talk about, etc. (This is a nice change from what was really a B or C+ course) You need to take this course if you build web apps -- .NET, Java, PHP, whatever. Take this course.

http://www.sans.org/vlive/details.php?nid=21094

Saturday, August 21, 2010

More SQL Injection Woes

These happen all the time, but hey it is in the headlines now so let's throw this one out to you as well. From SANS.org newsletter I get:



--Japanese Online Supermarket Database Hacked (August 15, 2010) Attackers reportedly used SQL injection attacks to steal customer information from the databases of eight Japanese online supermarkets.
The attacks took place in late July 2010. Some credit card companies have reported fraudulent activity on accounts compromised in the attacks.
http://www.japantoday.com/category/crime/view/hackers-steal-customer-data-by-accessing-supermarket-database

CLOSE THE SQL INJECTION HOLES PEOPLE! It is easy to do...parameterized queries! Email me if you aren't sure how to do them in ASP.NET.

Monday, August 9, 2010

Quiz #1 Answers - SQLi

OK, here are the answers...let me know how you did!

Q1. Parameterized queries are 100% effective against SQL Injection. True or False.

TRUE! SQLi is a PARSING issue, and using a parameterized query does not allow you to parse additional commands among your intended one.

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Q2. If you can't do parameterized queries, then you can do stored procedures in the database. They offer you the same level of protection. True or False.

FALSE! Though I recommend stored procedures to avoid mistakes on the business and data layer of .NET code, among other reasons, it is no guarantee the DBA coded the stored proc to use query parameters. He/she could still be concatenating the parameters as strings into a SQL command...ouch.

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Q3. Neither is perfect, but which is better for validation: black-listing or white-listing?

White-listing is better because you know what you want and can check for that, discarding anything else no matter how tricky the hackers try to get. If you black-list, you run a huge risk of missing tomorrow's new attacks, or of canonicalization errors where the hacker encodes the attack one layer deeper than where you look. Don't chase hackers, trying to learn their latest tricks...know your holes and plug them.

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Q4. If you thoroughly validate your input then you should be fine. True or False.

FALSE! Most validation is done client-side. And with javascript. Turn that off and see how your web page reacts. Even with good server-side validation, you have to accept strings sometimes...and those can be used to nail you with SQLi. That being said, you do make huge strides when you validate thoroughly...always do it! Makes your job of stopping them so much easier. It just isn't enough on its own to stop them, so don't rely on your best efforts as a "be all end all" sort of thing.

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Q5. Removing single-quotes from input data is an effective means of preventing SQLi. True or False.

FALSE! Well, true, but false. Getting rid of single quotes is one part of defense in depth. It will stop them from ending a string and putting a new command after it. Sure. But the hacker can encode it to hide it...are you checking for that? It can be part of a last name like O'Brien...do you let that through? Like other validation methods, it isn't enough to scrub out single quotes and sleep well at night.

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Q6. SQLi defense is like chasing a wind: by the time you figure out what to do it shifts and you have to do something else to protect your apps. True or False.

BIG FALSE! Go back to Q1. Make your queries parameterized. Done. It isn't hard. Like I said earlier, don't chase the wind...don't keep up on every hacker trick so you can be prepared for them. Instead know your holes and plug 'em. Analogy -- don't stay on top of what tools people are using to break into houses through windows. Instead, put bars on your windows, lock them, etc. Know what the holes are and plug them, rather than finding out what tools are being used and trying to thwart each of them.

SQL Injection is TOTALLY preventable. And it is YOUR responsibility to code for that. If you didn't get all the above correct, you are not alone. Just dig in more at sites like owasp.org and read up on SQL Injection...read how to do parameterized queries on MSDN...etc. You can do this!